Reliable and consistent laser diodes?

[The_Doctor]

I had a bust-up with my last 30 or so Rohm diodes, fed up with fiddly replacements after too many early failures. They are now unecologically seeding a nearby waste ground...

In the interests of preserving the environment, can anyone suggest the most stable, reliable single mode diode known for easy obtaining? I'm not after power, but that is nice too, good beam is more important, but ultimately they MUST be consistent, and cheap enough that I can reach for them the way I'll reach for an LF412 op-amp when I want to try something new. They don't have to be that cheap, but they must be easy to work with, and be known for long reliable active life. This is for red diodes, but also blue, if any have been around long enough yet to stand out as better for long life.

Basically, name the single mode diodes that have not disappointed you in some way. The ones you'd trust most, whatever their power is.

[krazer]

I use the predecessor to this laser http://www.newport.com/TLB-6700-Velo...1033/info.aspx, wouldn't want to be the person who originally paid for it though Granted, the linewidth on these is not so great (few megahertz measured over a few seconds), but it is rock solid as far as mode hopping, etc, it all depends on what you are trying to do with it.

If your application can be made to work in the IR, you can get 1550nm DFB lasers which have excellent linewidths for quite cheap (at least on the surplus market), and they come fiber coupled so the beam quality is perfect (limited only by the quality of your free space coupler), but sadly you can't get that kind of technology in the visible.

I will say that I have yet to find a basic fabry-perot diode laser that I really enjoyed working with (although all of the ones I have worked with have been from sacher laser, which while they can deliver cutting edge performance aren't really known for reliability), I would recommend switching to some sort of external cavity laser (ie, ECDL) if you really want something you can trust.

[steve-o]

I don't do low power stuff but I think mitsu has a nice 170mw one and I think there's a blue out there (and of course the 520 green ) ..
Check out DTR's Store here on PL .. He's got 3 in a package deal I believe .. I'll find the link and edit it to this post .. in a minute ..

-edit- ok here's the link :
https://sites.google.com/site/dtrlpf...gb-diode-budle

I *Think* they're all single mode and sturdy - not guaranteeing it , maybe someone will chime in .. who's more familiar with them .. (they are all 3.8mm I don't like the small-ish ones either) I find it easier to get them in the copper mounts , if you don't mind the 12mm "aixiz barrel" type .. personally I do like copper for heatsinking

Hey Doc- (off-topic) did you design the diode-driver using LM317s or LM338s that are up on LaserSam's FAQ site a few years ago under the name "LostGyfrellian" or something like that ? (I still can't spell it) ..

[swamidog]

they are all single mode.

i would not consider any diode to strudy.

I don't do low power stuff but I think mitsu has a nice 170mw one and I think there's a blue out there (and of course the 520 green ) ..
Check out DTR's Store here on PL .. He's got 3 in a package deal I believe .. I'll find the link and edit it to this post .. in a minute ..

-edit- ok here's the link :
https://sites.google.com/site/dtrlpf...gb-diode-budle

I *Think* they're all single mode and sturdy - not guaranteeing it , maybe someone will chime in .. who's more familiar with them .. (they are all 3.8mm I don't like the small-ish ones either) I find it easier to get them in the copper mounts , if you don't mind the 12mm "aixiz barrel" type .. personally I do like copper for heatsinking

Hey Doc- (off-topic) did you design the diode-driver using LM317s or LM338s that are up on LaserSam's FAQ site a few years ago under the name "LostGyfrellian" or something like that ? (I still can't spell it) ..

[absolom7691]

From personal experience, the Osram single-mode blues are not too sturdy. I popped one last weekend while hooking power to a P3 Flexmod. Granted I wasn't using a Lasorb but I have hooked up a lot of diodes this way, without a Lasorb with no problems, save for 405nm diodes which seem to die for no reason. With any diode, I would say it is important to slap a Lasorb on there. I'll be doing that before I wire up any more Osram SM blues from here on out.

[The_Doctor]

Thanks all, this is great! I thought the thread might slip quietly into oblivion as old subject matter.. Keep it coming, a solid consensus might be of big use to us here. I don't mean we have to agree, but some big picture of long term survival goes a long way. There are 'jelly bean' op-amps. Not so much with laser diodes. Yet......

Steve, yes. Sssh... Just quietly watching what becomes of that, and the quieter I do it the better. I'll answer stuff about it but I won't shout about it. Just want to see what take-up there is, if any.

EDIT. About 170mW singlemode 638nm reds, Oclara (was Opnext) do one. DTR hasn't got it, but might want to check it out. Prophotonix have it.. No idea about price though.

More edit:
Krazer, nothing special here. I just like the pretty light. Although there is the issue of mode hops. I can do without that. I think mode hopping is either related to fairly erratic cavity behaviour, or at least masks the subtle things to watch for when trying to push for more power. I have found this site very useful in making decisions about diodes in the past:
http://redlum.xohp.pagesperso-orange...eanalysis.html

[steve-o]

Steve, yes. Sssh... Just quietly watching what becomes of that, and the quieter I do it the better. I'll answer stuff about it but I won't shout about it. Just want to see what take-up there is, if any.

Yeah, I thought that was you! Very nice design. I love the old linear regulators in current mode. That's all I ever use for testing. They're great! The op-amp feedback you thought of is brilliant! Every engineer I talk to says that the LM3xx series "isn't designed for rapid modulation" . Proved 'em wrong eh? (I hope) .. I'll be building those (for personal use only) very soon I hope !! Thanx and cheerz !!!
PS- glad to see your back dude. The bug wont let go, will it .. Just need the pic of "House" for your av and we're all set again for good old times .. although your new av is very eerily interesting

[The_Doctor]

Awesome. Thanks for a strong vote of confidence. I can use it right now, so especially timely. And you're right, the laser bug persists through all my crises of confidence about what I'm going to do, and here I still be.. That House avatar may well be back again. But the current one is a strong contender, no? The BBC actually published the full size one on their website... It's based on a notion from an industrial band in Manhattan, called Bile. 'Demonic Electronic', ergo, this now being 'Demonic Photonic'. There were more of them... one with ghostly radiation symbols cast in green-lit fog. And at least one terrible pun attached. Incidentally, there may be boards ready made soon for that driver. Fortunately I'm getting excellent help with that, my own prototypes were few and not very pretty. There's also a 4.5K executable for quickly choosing the safe-limit resistance, as of about a week ago or so. Probably finished enough go public now, as it's not complex.

[steve-o]

Excellent.. I'd like 50 please .. (just kidding- unfortunately all cash is tied up in home repairs right now) .. do have enough in paypal to buy a few when they're available.. tho .. Oh, yeh like I did, quit paypal.. here it seems in the laser universe tho it's a necessary evil .. :/ .. I had to start again ..

[The_Doctor]

Don't make me fall over. You'll be ok when they're ready, they'll be on your side of the pond. Re Paypal, true indeed. I quit it two years ago, and for the first time I'm seriously wondering what I'm going to do about that. The Photonlexicon Bank? Now there's a notion might be worth exploring somehow...